Table 1. Physical fitness changes with bed rest.

Outcome	Total Sample (n = 18) 1					HDBR Control Subjects (n = 5) 2		HDBR Exercise Subjects (n = 13) 2		Control vs. Exercise 2
	Mean Pre HDBR	Mean Post HDBR	% Change	se % Change	p % Change	% Change	p % Change	% Change	p % Change	p Group Difference	Cohen’s D
Leg press	9380.1	8554.1	-8.4	2.56	0.004	-20.0	<0.001	-1.2	0.77	0.003	1.78
Jump	0.6	0.5	-8.0	2.27	0.003	-20.1	<0.001	-5.4	0.012	0.001	1.45
Knee	211.5	185.1	-12.1	2.53	<0.001	-20.3	<0.001	-3.0	0.28	0.008	1.56
Soleus	26.1	22.6	-13.4	1.84	<0.001	-24.8	<0.001	-8.1	<0.001	<0.001	2.86
VO2 max	3.1	2.8	-8.7	2.46	0.003	-17.1	0.001	-6.6	0.056	0.10	0.90
Fat mass	20.7	21.7	3.74	1.87	<0.001	11.1	<0.001	6.7	0.022	0.20	0.44

HDBR = head down bed rest; se = standard error; Leg press = isokinetic leg press total work over 21 reps (lbs); Jump = vertical jump (meter) divided by body weight (Kg); Knee = knee extension strength (nM); Soleus = Soleus muscle cross sectional area (cm²); VO₂ max = maximum rate of oxygen consumption during peak cycle (l/min); Fat mass = Fat mass percentage of total body weight;

¹ = analyzed using t-tests for the combined sample;

² = analyzed using regression analysis with group (exercise vs. control) as predictor and type of exercise as covariate of no interest